CTR was aware of difficulties with his dates. But while he was not prepared to move his Babylonian dates of 536 and 606, he was quite prepared to move the 1914 terminus by a full year to 1915. With its fixation at maintaining 1914, the GB shifted CTR’s Babylonian dates back by one year, to 537 and 607 respectively.
But Russell was not so concerned with the accuracy of 1914 and was quite prepared to move the terminus to 1915. He wrote the following in 1912, where he expected the END of the troubles on the Gentiles to take place by either October 1914 or October 1915. It also shows that CTR was fully aware of that there was no zero year, which is the WTS's excuse for shifting in 1942, the Fall of Babylon from 538 BCE to 539 BCE:
Here are CTR's words:
Coming now to a very critical examination of the date 536 B.C., there is an open question: Shall we call it 536 full years to A.D., or 535 full years? The difference in time between October 1st and January 1st would be the fourth of a year; hence our query is respecting 536-1/4 or 535-1/4 years B.C.
What is the proper method of calculation, is in dispute. If we count the first year B.C. as 0, then the date 536-1/4 B.C. is the proper one for the end of the seventy years of captivity. But if we begin to reckon it by counting the first year before the Christian era as B.C. 1, then evidently the desolation ended 535-1/4 years B.C.
As to the methods of counting, Encyclopaedia Britannica says, “Astronomers denote the year which preceded the first of our era as 0 and the year previous to that as B.C. 1--the previous year B.C. 2, and so on.”
Whichever of these ways we undertake to calculate the matter the difference between the results is one year. The seventy years of Jewish captivity ended October, 536 B.C., and if there were 536-1/4 years B.C., then to complete the 2,520 years’ cycle of the Times of the Gentiles would require 1913-3/4 years of A.D., or to October, 1914. But if the other way of reckoning were used, then there were but 535-1/4 years of the period B.C., and the remainder of the 2,520 years would reach to A.D., 1914-3/4 years, otherwise October, 1915.
Since this question is agitating the minds of a considerable number of the friends, we have presented it here in some detail. We remind the readers, however, that nothing in the Scriptures says definitely that the trouble upon the Gentiles will be accomplished before the close of the Times of the Gentiles, whether that be October, 1914, or October, 1915. (Watchtower, December 1, 1912, page 377, "The Ending of the Gentile Times").